<!-- 子组件 A：props + emit + slot -->
<template>
  <div class="card">
    <slot />
    <p>接收的消息：{{ msg }}</p>
    <button @click="$emit('reply', '收到父组件的消息啦！')">回复父组件</button>
  </div>
</template>

<script>
export default { name: 'CommChildA', props: { msg: String } }
</script>

<style>
.card { border:1px solid #ddd; padding:10px; margin:10px 0 }
</style>

